There are many different causes of swollen ankles. In most cases, swelling is due to injury or edema.

The term edema means swelling due to the accumulation of excess fluid. It is particularly common in the lower leg, ankles, and feet.

This article examines 12 causes of swollen ankles and covers some of the best treatment options.

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People who sustain an injury to the foot or ankle may experience inflammation in that area, causing it to appear swollen.

Ankle sprains are common, accounting for up to 40% of sports-related injuries.

The American Academy of Orthopaedic Surgeons recommends the following home treatment for a sprained ankle:

  • resting
  • immediately applying ice wrapped in a thin piece of cloth
  • applying a compression wrap, bandage, or dressing
  • elevating the foot above heart level
  • taking nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, to ease the pain and reduce swelling
  • wearing a walking boot or brace to provide ankle support

Bacterial infections in the skin are called cellulitis. People with diabetes are particularly prone to this type of infection.

Cellulitis can cause various symptoms, including redness, warm skin, and swelling that spreads rapidly. In rare cases, cellulitis can be life threatening without treatment.

People with cellulitis need to take antibiotics. It is essential to tell a doctor if the swelling does not reduce or gets worse after a few days of treatment.

Some medications can cause the ankles to swell as a side effect. Such medications include:

People who suspect their swollen ankle may be a side effect of medication may wish to talk with a doctor.

They may prescribe diuretic medications or suggest methods for reducing the swelling if it is uncomfortable.

Chronic venous insufficiency (CVI) is a common cause of edema. CVI is a condition that typically affects the valves in the leg veins but may occur in other locations.

CVI can be painful and uncomfortable. It may also cause noticeable changes to the skin.

These valves usually make sure that blood flows toward the heart. In CVI, the valves malfunction and allow blood to flow backward and pool in the lower legs and ankles.

A doctor can help a person with CVI develop a personalized treatment plan.

Examples of some treatment options include:

  • wearing compression stockings to reduce swelling and help heal skin ulcers
  • avoiding prolonged sitting or standing
  • keeping the legs raised to improve blood flow
  • walking or doing exercises that build the calf muscles
  • undergoing ablation, which uses heat or chemicals to destroy damaged veins

Sometimes, a blood clot, or thrombosis, can develop in one of the veins in the arm or leg. This is deep vein thrombosis (DVT) and requires urgent medical attention.

DVT obstructs the flow of blood returning to the heart, causing it to build up in the affected limb.

Sometimes, the body can compensate for the blockage by gradually diverting blood through smaller neighboring veins. Over time, these veins get larger and can drain blood from the limb.

If these veins do not increase in size, the limb may remain swollen. Persistent pain and swelling after a DVT is called post-thrombotic syndrome.

People who experience a DVT should consider:

  • elevating the affected limb
  • wearing compression stockings to promote blood flow
  • taking anticoagulant medications, or blood thinners
  • undergoing a stent procedure, during which a surgeon inserts a tube into the vein to keep it open

During pregnancy, the body produces more blood and bodily fluids to support the developing fetus.

Swelling is a common side effect of pregnancy, especially in the third trimester. It can affect the ankles, feet, legs, face, and hands.

Slight swelling is common and usually harmless. However, sudden swelling of the hands and face could signify a potentially life threatening condition called preeclampsia.

Women who experience mild swelling during pregnancy may get relief from home remedies such as:

Preeclampsia is a life threatening condition that can occur during the second or third trimester of pregnancy or up to 6 weeks after giving birth.

The condition involves dangerously high blood pressure and protein in the urine. It can cause various symptoms, including headaches, changes in vision, weight gain, and edema.

Preeclampsia that occurs during pregnancy can also affect the fetus.

It requires urgent medical treatment. Treatment may include medications to prevent seizures and lower blood pressure.

Delivering the baby is the most effective treatment, although some people may experience worsening symptoms before they get better.

Lymphedema is a swelling that affects the soft tissues in the arms or legs, including the ankles. It is due to a buildup of a fluid called lymph. This is mainly composed of white blood cells, which help fight infection.

Lymphedema occurs when there is a blockage or other damage to the lymphatic system. The lymphatic system is a network of tissues and organs that help rid the body of infection and keep fluids in balance.

Lymphedema can result from infections, cancer, and surgical removal of the lymph nodes. Some hereditary conditions can also cause lymphedema.

Damage to the lymphatic system is irreversible, so treatment aims to reduce swelling and prevent other symptoms.

Potential treatments include:

  • wearing pressure garments and bandages
  • increasing heart and respiration rate through exercise
  • getting a gentle massage from a trained therapist

Heart failure occurs when the heart can no longer pump blood as effectively as it should. There are three types of heart failure: left-sided, right-sided, and congestive heart failure.

In right-sided and congestive heart failure, a reduction in blood flow out of the heart causes blood to back up into the veins. This may lead to fluid buildup in tissues, including the legs and ankles.

Heart failure also affects the kidneys, reducing their ability to remove salt and water from the body. This further contributes to edema.

Although there is no cure for heart failure, many different treatment options and lifestyle changes can help people live with the condition.

A doctor may prescribe diuretic medications and suggest monitoring and reducing fluid intake. Both of these treatments can help reduce swelling in the ankles and legs.

Chronic kidney disease is permanent kidney damage, which can worsen over time.

A person may not experience symptoms until they are in the late stages of the disease, called kidney failure or end-stage renal disease (ESRD).

During ESRD, the kidneys struggle to remove waste and extra fluid from the body. This can lead to a range of symptoms, including swollen ankles.

The following lifestyle factors can also help maintain kidney function for as long as possible:

A healthy liver produces a protein called albumin. Albumin prevents fluid from leaking out of the blood vessels and surrounding tissues.

Very low albumin levels due to liver disease can cause a buildup of fluid in the legs, ankles, and abdomen.

A doctor may prescribe medications and advise on certain lifestyle factors that could help prevent or slow further liver damage. Examples include:

Hypothyroidism can affect a person’s muscles and joints, causing aches, pains, stiffness, and swelling.

If a person has hypothyroidism or an underactive thyroid, their thyroid gland produces too few hormones.

A 2017 study suggests there may be a link between thyroid disorders and rheumatoid arthritis, which can also cause painful joint swelling.

A doctor can perform a blood test to check a person’s thyroid hormone levels. Treatment involves taking synthetic thyroid hormones.

A person should contact a doctor if they have:

  • heat or discoloration in the swollen area
  • swelling that worsens or does not improve
  • a fever
  • a sudden increase in swelling during pregnancy
  • a history of heart, kidney, or liver disease

Many cases of edema, or swollen ankles, will resolve with proper home treatment.

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